Positive displacement machine such as a pump

ABSTRACT

A positive displacement machine such as a pump or compressor has a drum-like housing having an interior, circular-cylindrical surface symmetrical about a main axis and having a pair of interior, planar, side surfaces normal to the main axis. A drumlike rotor is mounted within the housing for rotation relative thereto about the main axis and has an exterior, circularcylindrical surface approximately fitting the interior, circularcylindrical housing surface. Also, the rotor has a pair of exterior, planar, side surfaces approximately fitting the interior, planar, side surfaces of the housing. Around the rotor is a peripheral groove symmetrical about a plane normal to the main axis and disposed between the planar side surfaces of the rotor. A ring having peripheral gaps therein is mounted on the housing and projects into and substantially occupies the groove. There are axially undulatory walls on the rotor defining a channel forming approximately sinusoidal pockets disposed on opposite sides of the ring and open thereto. The pockets have circumferentially overlapping portions and are circumferentially displaced from each other. The pockets when considered together have a substantially constant axial dimension. Vanes having substantially the same axial dimension are mounted on the housing for pivotal motion through the gaps and in the pockets as impelled by the channel walls. There are ports in the housing on axially opposite sides of the ring and on circumferentially opposite sides of the vanes defining inlet and outlet passages open to the pockets.

United States Patent 1 Williams Jan. 22, 1974 POSITIVE DISPLACEMENT MACHINE SUCH AS A PUMP [75] Inventor: Benjamin F. Williams, Douglas,

Ariz.

[73] Assignee: Benwi1co,lnc., Douglas, Ariz.

[22] Filed: Aug. 16, 1972 [211' Appl. No.: 280,944

[52] US. CL... 418/176, 418/211, 418/216, 418/245 [51] Int. Cl. F03c 3/00 {58] Field of Search... 418/211, 216,162, 218, 245, 418/247, 176

Primary Examiner-C. J. l-lusar [57] ABSTRACT A positive displacement machine such as a pump or compressor has a drum-like housing having an interior, circular-cylindrical surface symmetrical about a main axis and having a pair of interior, planar, side surfaces normal to the main axis. A drum-like rotor is mounted within the housing for rotation relative thereto about the main axis and has an exterior, circular-cylindrical surface approximately fitting the interior, circular-cylindrical housing surface. Also, the rotor has a pair of exterior, planar, side surfacesapproximately fitting the interior, planar, side surfaces of the housing. Around the rotor is a peripheral groove symmetrical about a plane normal to the main axis and disposed between the planar side surfaces of the rotor. A ring having peripheral gaps therein is mounted on the housing and projects into and substantially occupies the groove. There are axially undulatory walls on the rotor defining a channel forming approximately sinusoidal pockets disposed on opposite sides of the ring and open thereto. The pockets have circumferentially overlapping portions and are circumferentially displaced from each other. The pockets when considered together have a substantially constant axial dimension. Vanes having substantially the same axial dimension are mounted on the housing for pivotal motion through the gaps and in the pockets as impelled by the channel walls. There are ports in the housing on axially opposite sides of the ring and on circumferentially opposite sides of the vanes defining inlet and outlet passages open to the pockets.

7 Claims, 6 Drawing Figures mmmmzzmu 3787153 a Z F 37 I PATENIED m 2 2 1924 same of 2 POSITIVE DISPLACEMENT MACHINE SUCH AS A PUMP The positive displacement machine disclosed herein is related to the disclosure in my earlier US. Pat. No. 2,324,610 of July 20, 1943 and entitled Pump.

In various positive displacement devices such as compressors and pumps, for example, there is usually provided a rotor turning about an axis in a housing with some means for changing a contained volume so that it is varied in size between an inlet port and an outlet port. Thus induced gases or liquids may be compressed or displaced and then expelled. My earlier patent is an example of a device of this sort. In the earlier patent there is employed a particular sliding abutment member changed in position in time with the rotation of the rotor by means of a cam drum and follower as well as appropriate connecting mechanism. While this mechanism goes through the intended cycle without difficulty and produces an effective compressor or pump, it is somewhat more complex than now appears to be essential and has additional parts which are now not considered to be necessary.

It is therefore an object of the present invention to provide a compressor, pump or other positive displacement machine that is an improvement over the one disclosed in my mentioned patent.

Another object of the invention is to provide a positive displacement device that has a similar action to that of my earlier patented device but with fewer operating parts.

An additional object of the invention is to provide a simplified positive displacement machine.

Another object of the invention is to provide a positive displacement machine that is substantially selfcontained.

A further object of the invention is to provide a positive displacement machine that is easy to fabricate, maintain and repair.

A further object of the invention is to provide a positive displacement machine in which the frictional loss within the machine is reduced over that previously experienced.

A further object of the invention is to provide a more economical and generally more satisfactory positive displacement machine than has heretobefore been available.

Other objects together with the foregoing are attained in the embodiment of the invention described in the accompanying description and illustrated in the accompanying drawings, in which:

FIG. I is for the most part a cross-section on a vertical, axial plane through a positive displacement device pursuant to the invention, certain portions being shown in elevation;

FIG. 2 is a cross-section, the main plane of which is indicated by the line 22 of FIG. 1; and

FIGS. 3, 4, 5 and 6 are developments of the pump or compressor interior respectively showing the rotor in successive positions of operation.

While the positive displacement machine of the invention can be embodied in a number of different ways and for a number of different functions and purposes, it has with success been embodied as a pump or compressor as illustrated herein. In this embodiment, there is a drum-like housing generally designated 6, having a central portion 7 such as a footed casting to which a pair of side plates 8 and 9 are removably secured by fastenings 11. Both the center section 7 and the side plates 8 and 9 are generally symmetrical about a central, rotational axis 12. The housing 6 has a hollow configuration with interior, circular-cylindrical walls 13 having a finished surface held to close dimensions, the surface 13 being generally circular-cylindrical about the axis 12, and also is inclusive of a pair of side surfaces 14 and 16 that are substantially planar and are normal to the axis 12.

Within the drum and preferably part of the central section 7 thereof is an annular ring 17 having a pair of planar, side surfaces 18 and 19, both normal to the axis 12, and an interior, circular-cylindrical surface 2| circular about the axis [2.

Disposed within the housing so formed is a rotor 22 fixed on a shaft 23 designed to turn about the axis I2. The shaft 23 is mounted in anti-friction bearings 24 and 25 supported in boss portions of the side plates 8 and 9. The rotor 22 generally has circular-cylindrical, exterior surfaces 26 forming a close running, machined fit with the surfaces 13 and generally corresponding thereto. The rotor is also defined .by a pair of planar side surfaces 27 and 28 that are machined to occupy planes normal to the axis 12 and are aligned close to the side surfaces 14 and 16, the clearances between the surfaces being somewhat exaggerated in the drawing although well represented by central, annular portions 31 and 32 surrounding the bearings 24 and 25.

Particularly pursuant to the invention, the rotor has a central peripheral groove 33 partly defined by side walls 34 and 36 lying on opposite sides of and for the most part in close juxtaposition with the surfaces 18 and I9 of the planar ring 17. For that reason and to assist in machining and assembly, it is convenient to make the rotor of two parts removably fastened together by securing screws 37. The rotor, whether of one or two parts, is also particularly configured to define a circumferential, meandering or sinuous channel 38 of substantially rectangular, axial cross-section defined by side walls 39 and 40 and arranged so that the axial dimension across the channel at any particular portion thereof is substantially constant. The configuration of the channel with respect to solid portions of the rotor is such that the channel and the ring in effect define one or more pairs ofpockets 41 and 42. Conveniently, the walls of the channel are defined by elements that are normal to the axis 12 in every portion whereas the bottom of the channel is defined by circular-cylindrical surfaces 43 and 44 concentric with the axis 12.

Leading into the interior of the housing on opposite ends of at least one diameter thereof, for each pair of pockets and also on opposite sides of the center ring 17 are pairs of inlet ports 46 and outlet ports 47 generally opening to the rotor and particularly adapted to open into the pockets 41 and 42. The ports are preferably formed in flat pads 48 and 49 secured to the housing 6 and may be axially spaced so that at no time are the inlet ports and the outlet ports lapped circumferentially by a single pocket.

So that the various ports and pockets are appropriately connected to and isolated from each other in order that successive charges of intake air (or liquid) can be induced, trapped, compressed (or displaced) and expelled, I provide on opposite ends of a diameter of the housing a pair of vanes 51 and 52. These are substantially identical so that a description of one de scribes the other.

The vanes 51, for example, is an edge-contoured flat plate mounted on a pivot pin 53 having an axis 54 lying in the central plane of the housing and in a gap in the ring 17 and tangent to an imaginary circle centered on the axis 12. The pin serves as a pivotal mounting for the vane 51, the portion thereof near the pin being of substantially the same width as and disposed approximately within the thickness of the ring 17. From adjacent the region of the pin 53 the vane swells laterally, being defined by a pair of sides 56 and 57, preferably of arcuate contour, and terminates in an end surface 58 concentric with the axis 54 and merging smoothly with the sides 56 and 57. There are provided gaps 61 and 62 in the ring 17 so that the ring makes a close fit with the pivoted end of the vanes 51 and 52 and also with the upper arcuate surfaces 58 thereof as well as with the adjacent flat surfaces thereof. The other face of the vane runs on the pad. The dimension of the vane in the vicinity of the arcuate end surface 58 and measured directly thereacross is substantially the same as the axial dimension of the channel 38. The vane in all pivoted positions thereof substantially bears against the channel side walls and is impelled to rock or pivot about its pin mounting by the cam action of the channel side walls 39 and 40 as they advance during rotation of the rotor.

In the operation of this device a suitable rotary power source is coupled to the shaft 23 so that the shaft and rotor are revolved at the desired rate. As the rotor revolves the advancing channel walls oscillate or pivot the two vanes 51 and 52 to and fro. The positions of the vanes as the rotor turns are shown successively in FIGS. 3, 4, 5 and 6.

Assuming the position shown in FIG. 3 is a starting position with the vanes to the right and that the direction of rotor advance is as shown by the arrow 63, it is observed that the vanes 51 and 52 are being pivoted toward the left from the positions shown in FIG. 3. As the chamber 41 advances from the FIG. 3 position to the FIG. 4 position its volume against the vane 51 decreases thus inducing previously entrained air to flow out through the port 47. Simultaneously, the next pocket 41 draws in air from the port 46 and then expels that air through the next port 47. Also, the pocket 42 squeezes its air out through the port 47 and the cycle repeats with air being drawn into the subsequent pocket 42 through the related inlet 46. The vanes oscillate through the FIG. 3 to FIG. 6 positions and back again.

Depending upon the number of pockets, the number of oscillating or pivoting vanes and the number and position of the ports, it is possible to afford a plurality of pockets in the periphery of the rotor such that one or a number of segregated or entrapped portions of air are compressed or liquid is displaced for each rotation of the rotor.

It is customary in air pumping devices to have some lubricants supplied to the air and that is the case in this instance. Apart from the lubrication of the bearings 24, oil carried by the inspirated air coats the various interior, rubbing surfaces and supplies them with adequate lubrication. The net result is a rotary pumping or compressing mechanism that supplies a number of individual portions of air for each rotation with the air pressure having been increased from its inlet value to its outlet value, depending upon the particular capacity, shape and size of the pockets.

What is claimed is:

1. A positive displacement machine comprising a drum-like housing having an interior circularcylindrical surface symmetrical about a main axis and having a pair of interior planar surfaces normal to said main axis, a drum-like rotor, means for mounting said rotor within said housing and shaft means in torque transmitting relationship with said rotor for rotating said rotor about said main axis, said rotor having an exterior circular-cylindrical surface approximately fitting said interior circular-cylindrical surface and having a pair .of exterior planar surfaces approximately fitting said interior planar surfaces, means on said rotor defining a peripheral groove symmetrical about a plane normal to said main axis and disposed between said planar surfaces, a ring having peripheral gaps therein mounted on said housing and projecting into and substantially occupying said groove, means on said rotor including walls forming a sinuous channel defining a pair of pockets, said pockets being disposed on opposite sides of said ring and being open thereto, said pockets being axially and circumferentially displaced from each other, said pockets having inclined portions and said pockets considered together having a substantially constant axial dimension, vanes having substantially said axial dimension, means for mounting said vanes on said housing for pivotal motion in said gaps and in said pockets, and means in said housing on axially and circumferential opposite sides of said vanes defining ports adapted to communicate with said pockets.

2. A machine as in claim I in which said inclined portions have a camming engagement with said vanes.

3. A machine as in claim I in which said vanes are approximately T-shape and said vane mounting means includes a pivot pin at the bottom of the T.

4. A machine as in claim 3 in which the ends of said T have a camming engagement with said pocket walls.

53A r n ihiriea s hfclaim 1 in wl1 ic heacli of said vanes substantially occupies one of said gaps.

6. A machine as in claim 1 in which pivotal motion of said vanes is about a pin axis lying in said plane.

7. A machine as in claim 1 in which said pockets, said gaps, said vanes and said ports are duplicated at equal circumferential intervals around said main axis. 

1. A positive displacement machine comprising a drum-like housing having an interior circular-cylindrical surface symmetrical about a main axis and having a pair of interior planar surfaces normal to said main axis, a drum-like rotor, means for mounting said rotor within said housing and shaft means in torque transmitting relationship with said rotor for rotating said rotor about said main axis, said rotor having an exterior circular-cylindrical surface approximately fitting said interior circular-cylindrical surface and having a pair of exterior planar surfaces approximately fitting said interior planar surfaces, means on said rotor defining a peripheral groove symmetrical about a plane normal to said main axis and disposed between said planar surfaces, a ring having peripheral gaps therein mounted on said housing and projecting into and substantially occupying said groove, means on said rotor including walls forming a sinuous channel defining a pair of pockets, said pockets being disposed on opposite sides of said ring and being open thereto, said pockets being axially and circumferentially displaced from each other, said pockets having inclined portions and said pockets considered together having a substantially constant axial dimension, vanes having substantially said axial dimension, means for mounting said vanes on said housing for pivotal motion in said gaps and in said pockets, and means in said housing on axially and circumferential opposite sides of said vanes defining ports adapted to communicate with said pockets.
 2. A machine as in claim 1 in which said inclined portions have a camming engagement with said vanes.
 3. A machine as in claim 1 in which said vanes are approximately T-shape and said vane mounting means includes a pivot pin at the bottom of the T.
 4. A machine as in claim 3 in which the ends of said T have a camming engagement with said pocket walls.
 5. A machine as in claim 1 in which each of said vanes substantially occupies one of said gaps.
 6. A machine as in claim 1 in which pivotal motion of said vanes is about a pin axis lying in said plane.
 7. A machine as in claim 1 in which said pockets, said gaps, said vanes and said ports are duplicated at equal circumferential intervals around said main axis. 